U.S. Pat. No. 6,647,706 shows a baler with a rectangular baling chamber, in which a movable baling piston is arranged. The crop to be baled is supplied to the baling chamber through an inlet for the crop to be baled which is closed by a hold-back fork during a pre-compression of the harvested crop in a supply channel.
GB 2,219,967 B shows an alternative concept of a baler, where here several compression forks are provided that operate continuously, which are simultaneously used as loader forks and that are mechanically connected with the baling plunger in such a way that the baling plunger itself closes the inlet for the crop to be baled in the supply channel during the pre-compression of the harvested crop.
The problem underlying the invention is seen in the costly configuration of such balers.